Partially fluorinated liquid crystal material

ABSTRACT

The invention provides LC compositions that exhibit V-shaped switching when aligned in an analog device configuration and exhibit bistability when aligned in a bookshelf-type device configuration. The invention more specifically provides LC compositions of formula 1 and particularly chiral nonracemic compounds of formula 1 which exhibit bistable switching as well as V-shaped switching when aligned in appropriate device configurations. The invention also provides methods of using the compounds of the invention in making LC compositions and electooptical devices comprising an aligned layer of the compositions of this invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application takes priority under 35 U.S.C. 119(e) from U.S.provisional application No. 60/229,892 filed Sep. 1, 2000 which isincorporated by reference herein to the extent that it is notinconsistent with the disclosure of this application

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally liquid crystal compoundsand compositions and to optical devices employing liquid crystalcompositions in optical switching and display elements. The inventionmore specifically relates to antiferroelectric liquid crystalcompositions and improved liquid crystal compositions that exhibitV-shaped switching and bistable switching exhibiting very fast switchingspeeds and wide view angles useful in the preparation of LC opticaldevices. The invention also relates to analog and bistable LC opticaldevices that employ these compositions and which exhibit very fastswitching speeds and wide view angles.

[0003] Several types of smectic liquid crystal materials (LCs) have beeninvestigated for rapid switching, view-angle enhancement and highercontrast, including surface-stabilized ferroelectric LCs (FLCs),deformed helix ferroelectric LCs (DHFLCs), and antiferroelectric LCs(AFLCs). Recently, smectic material exhibiting thresholdless or moreproperly V-shaped switching LCs (VLCs) have been described (Inui, S. etal. (1996) J. Mater. Chem. 6(4):671-673; Seomun, S. S. et al. (1997)Jpn. J. Appl. Phys. 36:3580-3590).

[0004] Liquid crystal (LC) compositions exhibit one or more LC phases.LC compositions may be composed of one or more components. Components ofLC compositions may exhibit liquid crystal phases, have latent liquidcrystal phases or be compatible with (not suppress) liquid crystalphases in the LC composition. LC compounds and components of LC mixturesof this invention are rod-like molecules most typically having agenerally linear mesogenic core with one or more directly or indirectlylinked alicyclic or aromatic rings (which may be fused aromatic rings)and linear or branched tail groups distributed on either side of themesogenic core, e.g.:

[0005] LC components which do not themselves exhibit liquid crystalphases, but which exhibit LC phases on combination with one or moreother components are described as having “latent” liquid crystal phases.Chiral nonracemic LCs useful in FLC, DHFLC, AFLC and VLC compositionshave at least one component that has a chiral non-racemic tail group.FLC, DHFLC, AFLC and VLC compositions may be composed entirely of chiralnon-racemic components, but are typically composed of a mixture ofchiral nonracemic and achiral or racemic components.

[0006] Ferroelectric LCs when aligned parallel to the substrate surfacesusing the surface stabilized effect (in an surface-stabilizedferroelectric liquid crystal (SSFLC) device) exhibit two stable stateswitching on a microsecond time scale. Antiferroelectric LCs exhibitthree stable-state switching, which by application of a bias field canbe converted for use in a bistable switching mode LC devices. Two of theAFLC states have the same transmittance, so that alternate symmetricalswitching can be used in AFLC devices. VLCs, in contrast, exhibit veryrapid, analog electro-optic response, allow symmetrical driving, and nodc balance is required. VLCs are particularly attractive forapplications requiring generation of multiple levels of gray scale.

[0007] High quality full color images in a flat panel display requiresat least sixteen levels of gray scale. Temporal gray scale or partialdomain switching techniques have been used to adapt bistable state FLCdevices to multiple level gray scale applications. However, the numberof gray levels that can be generated with such methods is limited. Anelectroclinic effect, that has been observed in certain chiralnonracemic LC compositions possessing a smectic A phase, has also beenemployed to generated multiple gray scale levels. In an electroclinic LCdevice, application of an electric field to the LC in the chiral smecticA phases induces the LC molecules to tilt. The tilt angle is linearlyproportional to the applied electric field and results in the generationof analog gray scale. The induced tilt angle is, however, temperaturedependent and the maximum tilt angle available in most electrocliniccompositions is small requiring temperature control and limiting devicecontrast. In contrast, LC compositions exhibiting V-shaped switching canexhibit large tilt angles that are insensitive to temperature, and haveminimal hysterisis and minimal LC defects. These properties allowconstruction of LC devices with very fast response time, large viewingangle and high contrast.

[0008] V-shaped LC compositions and components of such compositions areuseful in a variety of optical device applications, including, inparticular, active matrix and thin film transistor display applications(e.g., flat-panel displays, computer monitors, head-mounted displays,cellular phone viewers), in analog beam deflectors (which can, e.g.,replace spinning mirrors in bar code scanners), for optical correlation,and for on-the-fly adaptive optics (for use, e.g., in astronomy androbotic vision).

[0009] The thresholdless effect was first observed by Inui et al. (1996)J. Mater. Chem. 6:671 in a three component antiferroelectric LC mixtureof compounds A:B:C (40:40:20 mass %):

[0010] It was later reported by Seong et al. (1997) J. Appl. Phys.36:3586-3590 that compound A in this mixture when homogeneously alignedin an LC cell exhibited V-shaped switching in an antiferroelectric phaseat certain temperatures.

[0011] Several models have been proposed to explain V-shaped switching.In one model, based on the association of V-shaped switching with LCshaving antiferroelectric phases, a distinct type of antiferroelectricphase is proposed to be the origin of V-shaped switching (Matsumoto T.,et al. (1999) J. Mater. Chem. 9:2051-2080). In this phase, the LCmolecules within a layer are uniformly tilted, but the tilt direction ofeach layer is randomly distributed, rather than layer correlated as inthe ordinary antiferroelectric phase. The analog electrooptic responseresults when LC molecules having different relative tilt orientationrespond differently to an applied field. As the field is increased moreand more molecules align with the applied field until the LC materialreaches the ferroelectric state. The randomly tilted phase wasdesignated a thresholdless antiferroelectric liquid crystal (TAFLC)phase.

[0012] In another model, the V-shaped switching phase is described as achevron-type smectic C phase (Parl, B. et al. (1999) Physical Review59(4):R3815). In this model at zero field, the LC molecules areuniformly aligned along the chevron interface. When an electric field isapplied the LC molecules rotate back and forth along a half cone abouttheir aligned orientation. Molecules rotate differently above and belowthe chevron interface resulting in an analog electrooptic response withincreasing field.

[0013] A third model is based on an experimental determination thatV-shaped switching can occur in a randomly tilted smectic C phase whichis aligned in a bookshelf layer structure between parallel substrates(Two Clarke et al. references). In this model, V-shaped switchingdepends upon the ability of the LC to form a bookshelf layer structureand high spontaneous polarization (Ps) of the LC. In the bookshelfgeometry with LC molecules exhibiting high Ps, the polarization orientsas a uniform block. When an electric field is applied the uniformpolarization block responds by azimuthal orientation of Ps on the tiltcone. Bookshelf geometry has previously been described in a class ofnaphthalene type LCs (U.S. Pat. No. 5,348,685 and Mochizuki et al.(1991) Ferroelectrics 122:37-51). A bookshelf layer structure can beformed in the smectic C phase when there is little or no shrinkage ofthe layer spacing on transition from the smectic A phase to the smecticC phase. Materials which exhibit a “deVries” type smectic A phase willform bookshelf layer geometry (U.S. provisional application, No.60/151,974, filed Sep. 1, 1999, U.S. application Ser. No. unassigned,attorney docket no. 57-00, filed Sep. 1, 2000 which is incorporated byreference in its entirety herein). A de Vries smectic A phase (theexistence of which was first suggested by de Vries, A. (1977) Mol.Cryst. Liq. Cryst. 41:27 and de Vries, A. (1979) Mol. Cryst. Liq. Cryst.4:179) consists of LC molecules whose directors are tilted with respectto the layer normal (rather than parallel to the layer normal in aregular smectic A phase). However, the titled LC molecules are randomlyoriented with respect to each other such that the average director ofthe LC is parallel to the layer normal. There is little shrinkage ontransition from a de Vries smectic A to a smectic C because the LCmolecules are already tilted. This third model suggests that V-shapedswitching will be associated with LC molecules which exhibit a de Vriessmectic A phase and possess high Ps.

[0014] U.S. Pat. No. 6,045,720 relates to LC compounds having the chiraltail:

[0015] where R₁ is CH₃, CF₃, CH₂F, CHF₂, m is 2-12 and R₂ is an alkylgroup having 1-10 carbon atoms with three-ring mesogenic cores whichexhibit an antiferroelectric phase. The mesogenic core can containphenyl, various F-substituted phenyl, pyridine rings and cyclohexyrings. The achiral tail is an alkyl or alkoxy group. Certain compoundsof the invention are reported to exhibit low threshold switching.

[0016] Several models have been proposed to explain V-shaped switching.In one model, based on the association of V-shaped switching with LCshaving antiferroelectric phases, a distinct type of antiferroelectricphase is proposed to be the origin of V-shaped switching.

[0017] U.S. Pat. No. 5,938,973 relates to certain ferrielectric LCcompositions containing certain swallow-tailed LC compounds. Thecomposition also contains certain chiral LC compounds having a chiraltail group of Formula D:

[0018] where A is CF₃ and B is certain ether groups. The mesogenic coreis a phenyl benzoate core which may be substituted with one fluorine andthe other tail group is an alkoxy group. The reference reports anapparently continuous change in transmission in on application ofvoltage between 0 and 4 volts. It is suggested that the continuouschange in transmission as a function of voltage results because thethreshold voltage between ferroelectric and antiferroelectric states inthe LC composition is “not distinct.”

[0019] U.S. Pat. No. 5,728,864 relates to LC compounds or compositionshaving a ferrielectric phase. The LC compounds have a biphenyl benzoatecore optionally substituted with one fluorine with a chiral tail offormula D where A is CF₃ or C₂F₅ and B is certain ether and an achiraltail that is a linear alkoxy group.

[0020] U.S. Pat. No. 6,002,042 relates to compounds having anantiferroelectric or a ferrielectric phase that are biphenyl benzoatesoptionally substituted with one fluorine with a chiral tail group offormula D where A is CF₃ and B is certain alkyl groups and the othertail group is a linear alkoxy group.

[0021] A number of additional compounds having biphenyl benzoate coresand the same or a similar chiral or achiral tail group D (above) where Ais —CF₃, —CH₃, —C₂H₅, and B is various alkyl or ether groups and whenthe compound is chiral * indicates the chiral carbon. U.S. Pat. No.5,340,498 relates to compounds having certain fluorine substitution onthe phenyl benzoate core and ether groups.

[0022] U.S. Pat. Nos. 5,980780 and 5,985,172 relate to antiferroelectricLC compositions containing certain racemic phenyl benzoate compounds incombination with compounds having a biphenyl benzoate core optionallysubstituted with one fluorine and having a chiral tail of formula Dwhere A is —CF₃ or —CH₃ and B is certain alkyl or ether tails.

[0023] U.S. Pat. No. 6,018,070 relates to antiferroelectric LC compounds(which may be optically active) having a two-ring phenyl ester corewhich may have certain fluorine substituents on the ring where one tailis an alkyl ester and the other tail is the tail of formula D where A is—CH₃ or −CF₃ and B can be certain alkyl or ether groups.

[0024] U.S. Pat. No. 6,001,278 relates to certain antiferroelectric LCcompositions containing certain swallow-tailed LC compounds. Thecomposition also contains certain antiferroelectric LC compounds havinga chiral tail group of Formula D where A is CH₃ or CF₃ and B is certainalkyl or ether groups. The mesogenic core is a phenyl benzoate corewhich may be substituted with one fluorine and the other tail is analkyl ester tail.

SUMMARY OF THE INVENTION

[0025] In one aspect this invention relates to antiferroelectric liquidcrystal (LC) compositions exhibiting very fast switching speeds,preferably faster than 1 msec and wide view angles, preferably greaterin magnitude than 70°, useful in the preparation of LC optical devices.In another aspect the invention relates to liquid crystal compositionswhich exhibit V-shaped switching with very fast switching speeds andwide view angles useful in the preparation of analog LC optical devices.LC compositions of this invention exhibiting V-shaped switching can alsoexhibit bistable switching in appropriate device configurations. Theinvention also relates to analog and bistable LC optical devices thatemploy the antiferroelectric and V-shaped switching compositions of thisinvention. LC-based devices employing the compositions of this inventioncan be operated at low driving voltages (<3V/μtm) and at high frequency(>10 Hz). LC-based devices of this invention can also be operated usinga symmetrical driving scheme thereby affording DC balance.

[0026] Antiferroelectric liquid crystal compositions of this inventioncomprise one or more chiral non-racemic compounds of the formula:

[0027] where:

[0028] R is a linear or branched perfluorinated or partially fluorinatedalkyl group (R^(F)), a linear, cyclic or branched perfluorinated orpartially fluorinated ether group or a linear or branched ether group;

[0029] Rings A, B and C are 6-carbon aromatic rings each optionallysubstituted with from one to four fluorines and wherein one or two CHgroups in the rings can be substituted with a N;

[0030] d is 0 or 1;

[0031] D is a linker group selected from the group consisting of —COO—,—OOC—, —CH₂—CH₂—, a cis or trans double bond, or a triple bond, when dis 0 rings B and C are linked through a single bond;

[0032] Y is an alkyl or fluorinated alkyl group having from one to sixcarbon atoms; and

[0033] R¹ is a nonchiral tail group selected from linear or branchedalkyl groups where one or more non-neighboring CH₂ groups can bereplaced with an —O—, —S—, —Si(R′)₂—, —Si(R′)₂—(CH₂)_(P)—Si(R′)₂—, wherep is an integer ranging from 1 to 6, —Si(R′)₂—O—, —Si(R′)₂—O—Si(R′)₂—O—,a cis or trans double bond or a triple bond, wherein each R¹,independent of other R′, is an alkyl or fluorinated alkyl group havingfrom one to six carbon atoms and wherein the R¹ tail group is optionallysubstituted with one or more fluorines.

[0034] Rings A, B and C are exemplified by those in Scheme 1. VariousA-B ring combinations are exemplified in Scheme 2. Various corestructures containing rings A, B and C are illustrated in Scheme 3.Although only trans —CH₂═CH₂— linked cores are illustrated in Scheme 3,the corresponding cis-linked cores can also be employed in mixtures ofthis invention.

[0035] LC compositions of this invention include those of comprising oneor more compounds of Formula 1 in which:

[0036] R is a perfluorinated or partially fluorinated ether;

[0037] R is an ether group;

[0038] R is R^(F);

[0039] R═R^(F) is a partially fluorinated alkyl group having from 1 toabout 20 carbon atoms;

[0040] R═R^(F) is a partially fluorinated alkyl group having from 3 toabout 20 carbon atoms;

[0041] R═R^(F) has the formula: C_(n)F_(2n+1)C_(m)H_(2m)— wherein n isan integer ranging from 1 to about

[0042] 10 and m is an integer ranging from 0 to about 10;

[0043] R═R^(F) has the formula: C_(n)F_(2n+1)C_(m)H_(2m)— wherein n isan integer ranging from 1 to about 10 and m is an integer ranging from 0to about 10;

[0044] R═R^(F) is C_(n)F_(2n+1)—C_(m)H_(2m+1)— wherein n and m are 4-6;

[0045] One of rings A, B or C is a pyrimidine;

[0046] One of rings A, B or C is a pyridine;

[0047] All of rings A, B and C are optionally substituted phenyls;

[0048] One of rings A, B and C are substituted with one or twofluorines;

[0049] Two of rings A, B and C are substituted with one or twofluorines;

[0050] One of rings A, B and C are substituted with two fluorines;

[0051] d is 1 and D is —OOC—;

[0052] d is 1 and D is —COO—;

[0053] d is 1 and D is —CH₂—CH₂—

[0054] d is 1 and D is a trans double bond;

[0055] d is 0;

[0056] Y is a small alkyl or fluorinated alkyl group having from 1 to 3carbon atoms;

[0057] Y is CF₃— or C₂F₅—;

[0058] Y is CF₃;

[0059] Y is a small alkyl group having from 1 to 3 carbon atoms;

[0060] Y is CH₃—;

[0061] Y is C₂H₅—;

[0062] Y is C₃H₇—;

[0063] R¹ is a group having 3 to 20 carbon atoms;

[0064] R₁ is a linear or branched alkyl group having from 1 to 20 carbonatoms;

[0065] R₁ is a linear alkyl group having from 5 to 10 carbon atoms;

[0066] R₁ is a branched alkyl group having from 5 to 10 carbon atoms;

[0067] R₁ is an ether group having 1 to 3 oxygen atoms;

[0068] R₁ is a thioether group having 3 to 20 carbon atoms;

[0069] R₁ is an alkene group having 3 to 20 carbon atoms;

[0070] R₁ is an alkyne group having 3 to 20 carbon atoms;

[0071] R₁ is an alkyl group having from 3 to about 10 carbon atoms;

[0072] R₁ is an alkyl group optionally substituted with one or morefluorines and having from 1 to about 20 carbon atoms;

[0073] R₁ is an olefin containing one or two cis or trans double bonds;

[0074] R₁ contains at least one Si atom;

[0075] R₁ contains a —Si(R′)₂—(CH₂)_(p)—Si(R′)₂— group where p is 1-6and R′ is a small alkyl group having from 1 to 3 carbon atoms;

[0076] R₁ contains a —Si(R′)₂—CH₂—Si(R′)₂— group where R′ is a smallalkyl group having from 1 to 3 carbon atoms;

[0077] R₁ contains a —Si(R′)₂—O— group where R′ is a small alkyl grouphaving from 1 to 3 carbon atoms;

[0078] R₁ contains a —Si(R′)₂—O—Si(R′)₂— group where R′ is a small alkylgroup having from 1 to 3 carbon atoms;

[0079] R₁ is a partially fluorinated alkyl group having from 1 to 20carbon atoms;

[0080] R₁ is a perfluorinated alkyl group having from 1 to 20 carbonatoms; or any combination of A, B or C rings, linking group D, R, R^(F),R¹ and Y as above-defined.

[0081] In specific embodiments; the liquid crystal compounds of thisinvention comprise one or more chiral non-racemic compounds of Formula 1in which R is R^(F) and:

[0082] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 and R¹is an alkyl group having from 3 to about 10 carbon atoms;

[0083] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10, Y isCF₃— and R¹ is an alkyl group having from 3 to about 10 carbon atoms;

[0084] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a biphenyl group;

[0085] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a phenyl pyridine group;

[0086] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a phenyl pyrimidine group;

[0087] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a biphenyl group that is substituted withone to four fluorines;

[0088] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a phenyl pyridine group that is substitutedwith one to four fluorines; or

[0089] R is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andrings A and B together form a phenyl pyrimidine group that issubstituted with one to four fluorines.

[0090] In other specific embodiments; the liquid crystal compounds ofthis invention comprise one or more chiral non-racemic compounds ofFormula 1 in which R is an ether group which may contain one or more —O—and which may be fully or partially fluorinated. An ether group includesgenerally linear, branched or cyclic alkyl groups in which one or more—CH₂— groups are replaced with —O—. In this case R can include, but isnot limited to:

[0091] C_(q)H_(2q+1)—O—C_(r)H_(2r)—, where q and r are integers from 1to 20 and more preferably are integers from 3 to 8;

[0092] C_(q)H_(2q+1)—O—C_(r)H_(2r)—O—C_(s)H_(2s)—, where q, r and s areintegers from 1 to 20 and more preferably are integers from 2 to 8;

[0093] C_(q)F_(2q+1)—O—C_(r)H_(2r)—, where q and r are an integers from1 to 20 and more preferably are integers from 3 to 8;

[0094] C_(q)H_(2q+1)—O—C_(r)F_(2r)—, where q and r are integers from 1to 20 and more preferably are integers from3 to 8;

[0095] C_(q)F_(2q+1)—O—C_(r)H_(2r)—O—C_(H) _(2s)—, where q, r and s areintegers from 1 to 20 and more preferably are integers from 2 to 8;

[0096] C_(q)H_(2q+1)—O—C_(r)F_(2r)—O—C_(s)H_(2s)—, where q, r and s areintegers from 1 to 20 and more preferably are integers from 2 to 8;

[0097] C_(q)H_(2q+1)—O—C_(r)H_(2r)—O—C_(s)F_(2s)—, where q, r and s areintegers from 1 to 20 and more preferably are integers from 2 to 8;

[0098] C_(q)F_(2q+1)—O—C_(r)F_(2r)—, where q and r are integers from 1to 20 and more preferably are integers from 3 to 8; or

[0099] C_(q)F_(2q+1)—O—C_(r)F_(2r)—O—C_(s)F_(2s)—, where p, q and r areintegers from 1 to 20 and more preferably are integers from 2 to 8.

[0100] LC compositions of this invention include those exhibiting anantiferroelectric phase and comprising one or more compounds of Formula1 in which the mesogenic core formed by rings A, B, C and optionallinker D is illustrated in Scheme 3. A subset of Compounds of Formula 1of particular interest are those in which R is RF and the mesogenic coreformed by rings A, B, C and optional linker D is illustrated in Scheme3.

[0101] Liquid crystal compositions of this invention also includecompositions exhibiting V-shaped switching and comprising one or morecompounds of formula 1. LC compositions of this invention also includecompositions that form layers with low angle where the chevron angle isless than or equal to about 18° as well as compositions that form layersthat are substantially chevron-free (where the chevron angle is lessthan about 12° ) in a surface stabilized ferroelectric LC (SSFLC)device. Liquid crystal compositions of this invention also includecompositions that exhibit V-shaped switching when introduced into ananalog LC device configuration and bistable switching when introducedinto a surface-stabilized LC device.

[0102] Liquid crystal compositions of this invention include thosecomprising one or more compounds of Formula 1 and which exhibitproperties improved for electrooptical applications. LC compositionsinclude those that exhibit high polarization (Ps), i.e., Ps of 27 nC/cm²or greater or preferably a Ps of 40 nC/cm² or greater; those thatexhibit fast rise times, i.e., 150 μsec or less, those that exhibit lowviscosity of 200 mP*S or less; and those that exhibit desirable phasesover broader temperature ranges, e.g., those exhibiting a smectic Aphase which extends over a range of 20° C. or more, and those whichexhibit desirable phases at temperatures that are more convenient fordevice operation (e.g., desirable phases at room temperature).

[0103] The invention further provides LC devices including bistable andanalog devices which comprise LC compositions comprising one or morecompounds of Formula 1. Of particular interest are optical devices whichcomprise an LC composition of this invention which exhibits V-shapedswitching in an analog device configuration and bistable switching in asurface-stabilized device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0104]FIG. 1 is a graph illustrating the voltage dependence of switchingangle in a representative compound of this invention, MDW 1228. Theinset graph is an expansion of the switching angle dependence from 0 to1.0 volt.

[0105]FIG. 2 is a graph of tilt angle as a function of temperature (°C.) showing the layer spacing in MDW1228.

DETAILED DESCRIPTION OF THE INVENTION

[0106] Preferred compositions of this invention for V-shaped switchinginclude those compositions that comprise one or more compounds of thisinvention of formula 2A:

[0107] where variables take values as defined for formula 1 and in morespecific embodiments:

[0108] R is a linear, branched or cyclic ether which may beperfluorinated ro partially fluorinated;

[0109] R═R^(F) is a linear or branched fluorinated or partiallyfluorinated alkyl group;

[0110] X¹⁻⁴ are hydrogens or fluorines;

[0111] Ring C is a phenyl ring optionally substituted with from one tofour fluorines and wherein one or two CH groups in the rings can besubstituted with a N;

[0112] d is o or 1;

[0113] D is a linker group selected from the group consisting of —COO—,—OOC—, —CH₂—CH₂—, a cis or trans double bond, or a triple bond, when dis 0 rings B and C are linked through a single bond; Y is an alkyl orperfluorinated alkyl group having from 1 to 6 carbon atoms; and

[0114] R¹ is a nonchiral group selected from linear or branched alkylgroups where one or more non-neighboring CH₂ groups can be replaced withan —O—, —S—, —Si(R′)₂—, —Si(R′)₂—O—, —Si—(R′)₂—(CH₂)p_Si(R′)₂—, where pis an integer ranging from 1 to 6, —Si(R′)₂—O—Si(R′) ₂—, a cis or transdouble bond or a triple bond and wherein the R¹ tail group is optionallysubstituted with one or more fluorines.

[0115] Ring C is exemplified by those rings in Schemel.

[0116] LC compositions of Formula 2A include those in which R is R^(F)and:

[0117] R^(F) is a partially fluorinated alkyl group having from 1 toabout 20 carbon atoms;

[0118] R^(F) is a partially fluorinated alkyl group having from 3 toabout 20 carbon atoms;

[0119] R^(F) has the formula: C_(n)F_(2n+1)C_(m)H_(2m) wherein n is aninteger ranging from 1 to about 10 and m is an integer ranging from 0 toabout 10;

[0120] R^(F) has the formula: C_(n)F_(2n+1)C_(m)H_(2m)— wherein n is aninteger ranging from 1 to about 10 and m is an integer ranging from 0 toabout 10;

[0121] R^(F) is C_(n)F_(2n+1)—C_(m)H_(2m)— wherein n and m are 4-6;

[0122] Ring C is a phenyl ring;

[0123] Ring C is a pyrimidine;

[0124] Ring C is a pyridine;

[0125] Ring C is substituted with one or two fluorines;

[0126] d is 1 and D is —OOC—;

[0127] d is 1 and D is —COO—;

[0128] d is 0;

[0129] X¹ and X² are F and X³ and X⁴ are hydrogen,

[0130] Y is CF₃,

[0131] Y is a small alkyl group having from 1 to 3 carbon atoms;

[0132] Y is CH₃—;

[0133] Y is C₂H₅—;

[0134] Y is C₃H₇—;

[0135] R¹ is a group having 3 to 20 carbon atoms;

[0136] R₁ is a linear or branched alkyl group having from 1 to 20 carbonatoms;

[0137] R₁ is a linear alkyl group having from 5 to 10 carbon atoms;

[0138] R₁ is a branched alkyl group having from 5 to 10 carbon atoms;

[0139] R₁ is an ether group having 1 to 3 oxygen atoms;

[0140] R₁ is a thioether group having 3 to 20 carbon atoms;

[0141] R₁ is an alkene group having 3 to 20 carbon atoms;

[0142] R₁ is an alkyne group having 3 to 20 carbon atoms;

[0143] R¹ is an alkyl group having from 3 to about 10 carbon atoms;

[0144] R¹ is an alkyl group optionally substituted with one or morefluorines and having from 1 to about 20 carbon atoms;

[0145] R¹ is an olefin containing one or two cis or trans double bonds;

[0146] R₁ contains at least one Si atom;

[0147] R₁ contains a —Si(R′)₂—(CH₂)_(p)—Si(R′)₂— group where p is 1-6and R′ is a small alkyl group having from 1 to 3 carbon atoms;

[0148] R₁ contains a —Si(R′)₂—CH₂—Si(R′)₂′ group where R′ is a smallalkyl group having from 1 to 3 carbon atoms;

[0149] R₁ contains a —Si(R′)₂—O— group where R′ is a small alkyl grouphaving from 1 to 3 carbon atoms;

[0150] R₁ contains a —Si(R′)₂—O—Si(R′)₂— group where R′ is a small alkylgroup having from 1 to 3 carbon atoms;

[0151] R₁ is a partially fluorinated alkyl group having from 1 to 20carbon atoms;

[0152] R₁ is a perfluorinated alkyl group having from 1 to 20 carbonatoms; or

[0153] R′ is a methyl group; or any combination of C ring, X¹⁻³, lininggroup D, R^(F), R¹, R′ and Y as above-defined.

[0154] In specific embodiments, the compounds of formula 2A includethose in which R is R^(F) and:

[0155] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range

[0156] from 1 to about 10 and R¹ is an alkyl group having from 3 toabout 10 carbon atoms;

[0157] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range

[0158] from 1 to about 10, Y is CF₃— and R¹ is an alkyl group havingfrom 3 to about 10 carbon atoms;

[0159] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range

[0160] from 1 to about 10, Y is CH₃— and R¹ is an alkyl group havingfrom 3 to about 10 carbon atoms;

[0161] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10, Y isC₃H₇— and R¹ is an alkyl group having from 3 to about 10 carbon atoms;

[0162] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10, and R¹is a group having the formula:

—(CH₂)_(p)—Si(R′)₂—O—Si(R′)₂—R′,

[0163]  where p is an integer ranging from 2-10 and R′ is a small alkylor perfluoroalkyl group having from 1 to 3 carbon atoms;

[0164] R^(F) is a partially fluorinated tail group of formulaC_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10, and R¹is a group having the formula:

—(CH₂)_(p)—Si(CH₃)₂—O—Si(CH₃)₃,

[0165]  where p is an integer ranging from 2-10;

[0166] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 and X¹and X² are fluorines;

[0167] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 and X³and X⁴ are fluorines;

[0168] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 andRing C is a phenyl ring optionally substituted with one or twofluorines;

[0169] R^(F) is a partially fluorinated alkyl group of the formulaC₄F₉—(CH₂)_(m), where m is an integer ranging from 2 to 8;

[0170] R^(F) is a partially fluorinated alkyl group of the formulaC₆F₁₃—(CH₂)_(m), where m is an integer ranging from 2 to 8; or

[0171] R^(F) is a partially fluorinated alkyl group of the formulaCF₃—(CH₂)_(m), where m is an integer ranging from 2 to 10.

[0172] In other specific embodiments, the compounds of formula 2Ainclude those having the formula:

[0173] where variables are as defined for formula 1 and 2A and where inmore specific embodiments:

[0174] R^(F) is a partially fluorinated alkyl group;

[0175] R^(F) is a partially fluorinated tail of the formula:C_(n)F_(2n+1)C_(m)H_(2m)— where n and m range from 1 to about 10 and R¹is an alkyl group having from 3 to about 10 carbon atoms;

[0176] X¹-X⁶ are fluorines or hydrogens and at least one of X¹-X⁶ is afluorine and Y is CF₃—,

[0177] C₂F₅—, CH₃—, C₂H₅—, or C₃H₇—;

[0178] X¹ and X² are fluorines and X³-X⁵ are hydrogens;

[0179] X¹-X⁴ and X⁶ are hydrogens and X⁵ is fluorine;

[0180] X¹, X² and X⁶ are hydrogens and X³-X⁵ are fluorines;

[0181] X¹, X² and X⁵ are fluorines and X³, X⁴ and X⁶ are hydrogens;

[0182] Y is CF₃—;

[0183] Y is a small alkyl group having from 1 to 3 carbon atoms;

[0184] Y is CH₃—;

[0185] Y is C₂H₅—;

[0186] Y is C₃H₇—;

[0187] R¹ is an alkyl or ether group having from 3 to 20 carbon atoms;

[0188] R^(F) is a partially fluorinated alkyl group, Y is CF₃— and X¹-X²are fluorines; or

[0189] R^(F) is a partially fluorinated alkyl group, Y is CF₃-X¹⁻² arefluorines, X³⁻⁵ are hydrogens and R¹ is an alkyl group.

[0190] Preferred compounds of formulas 2A and 2B are chiral nonracemiccompounds where * indicates the chiral carbon. Each compound of formulas2A and 2B has two enantiomers. Chiral nonracemic compound of eitherenantiomeric form can be employed.

[0191] In specific embodiments, the invention further provides compoundsof formulas 3A-D:

[0192] where variables are as defined above for formulas 1 and 2A-B andin more specific embodiments:

[0193] R^(F) is a partially fluorinated group of formula:C_(n)F_(2n+1)C_(m)H_(2m)—;

[0194] R^(F) is CF₃—C_(m)H_(2m)— where m is 4-10;

[0195] R^(F) is C₂F₅—C_(m)H_(2m)— where m is 3-10;

[0196] R^(F) is C₄F₉—C_(m)H_(2m)— where m is 1-10;

[0197] R^(F) is C₆F₁₃—C_(m)H_(2m)— where m is 1-10;

[0198] Y^(F) is CF₃—;

[0199] Y is CH₃—;

[0200] Y is C₃H₇—;

[0201] R¹ is a linear alkyl group having 3 to 7 carbon atoms;

[0202] R¹ is C₆H₁₃—;

[0203] R¹ is a group having the formula: —(CH₂)_(p)—Si(R′)₂—O—Si(R′)₂—R′where p is an integer ranging from 2-10 and R′ is a small alkyl group;

[0204] R¹ is a group having the formula: —(CH₂)_(p—si(CH) ₃)₂—O—Si(CH₃)₃where p is an integer ranging from 2-10;

[0205] R¹ is a group having the formula: —(CH₂)_(p)—Si(CH₃)₂—O—Si(CH₃)₃where p is 3-6; or

[0206] R¹ is a group having the formula: —(CH₂)₅—Si(CH₃)₂—O—Si(CH₃)₃.

[0207] Preferred compounds of formulas 3A-3D are chiral nonracemiccompounds where * indicates the chiral carbon. Each compound of formulas3A, 3B, 3C and 3D has two enantiomers. Chiral nonracemic compound ofeither enantiomeric form can be employed.

[0208] In the compounds of formulas 2A, 2B, and 3A-D, R¹ can be an alkylgroup having from 1 to about 20 carbon atoms; R¹ can be an alkyl grouphaving from 3 to about 10 carbon atoms; R¹ can be an alkyl groupoptionally substituted with one or more fluorines having from 1 to about20 carbon atoms; or R¹ can be a perfluorinated alkyl group having from 1to about 20 carbon atoms.

[0209] The invention encompasses liquid crystal materials, including FLCmaterials and including FLC materials exhibiting a smectic C phase,comprising one or more of the compounds of this invention andparticularly one or more compounds of formulas 2A, 2B, 3A, 3B, 3C or 3D.Enantiomers and racemates of specifically described compounds are alsoencompassed by the invention.

[0210] LC compositions include those having 5% by weight or more of oneor more compounds of this invention (of Formula 1) wherein the addedcompound or combination of compounds has an effect and preferably asignificant effect upon the LC properties of the mixture. LC propertiesof particular interest include melting temperature, freezingtemperature, phase transition temperatures, temperature range of a givenphase (e.g., of the smectic C or smectic A phase), and ease ofalignment. For purposes of this invention a significant effect on atransition temperature is a change of ±5° C. For purposes of thisinvention a significant effect on the temperature range of a given phaseis a broadening or narrowing of a phase range by ±5° C. Compounds ofthis invention that are achiral or racemic can be employed as hostmixtures for addition of appropriate chiral nonracemic materials (e.g.,chiral nonracemic compounds of this invention). In particular, LCcompositions of this invention include those having 5% by weight or moreof a compound of this invention (of Formula 1) and which exhibit a deVries smectic A phase.

[0211] Preferred mixtures of this invention have 25% by weight or moreof one or more chiral nonracemic compounds of this invention (of Formula1). The mixture optionally contains one or more chiral nonracemic LCcompounds, particularly those that enhance polarization of the mixture.The total amount of combined chiral nonracemic components in a mixtureis typically 65% or less. Exemplary chiral nonracemic LC additives formixtures of this invention are illustrated in Schemes 6 and 7. Theremaining components (racemic or achiral) of the mixtures form anappropriate host mixture.

[0212] Host mixture components are selected in general to achievedesirable phase properties for a given device application. Hostcomponents can affect, among other properties, viscosity (and indirectlyswitching speed), tilt angle, phase transition temperatures and thebreadth of phases exhibited by the mixtures. Exemplary components for LCmixtures of this invention are illustrated in Schemes 6 and 7. Preferredcomponents are those such as those exemplified in Scheme 6 and 7 whichare compatible with a de Vries smectic A phase (i.e., do not suppressthe phase) and which are compatible with V-shaped switching.

[0213] Mixtures of this invention include those comprising 50% by weightor more of one or more compounds of this invention (of Formula 1) andthose containing 45% or more of one or more compounds of this invention.A preferred subset of mixtures of this invention are those that containfrom about 25% to about 50% by weight of more or more components of thisinvention. Mixtures of this invention also include those that consistessentially of two or more compounds of this invention and particularlythose mixtures exhibiting a de Vries smectic A phase.

[0214] Mixtures of this invention can include one or more chiralnon-racemic compounds of Formula 1 in combination with a host mixture,compatible for mixing with the chiral non-racemic compounds, whichcomprises two or more achiral or chiral racemic compounds of Formula 1.

[0215] The invention also encompasses bistable SSFLC devices and analogswitching devices comprising an aligned FLC layer comprising one or morecompounds (of Formula 1) of this invention. The invention alsoencompasses bistable SSFLC devices and analog switching devicescomprising an aligned FLC layer comprising one or more compounds of anyof Formulas 2A, 2B, 3A, 3B, 3C or 3D.

[0216] Scheme 4 lists a number of exemplary chiral nonracemic compoundsof this invention and provides exemplary phase diagram data for liquidcrystal materials of this invention. Scheme 4 more the most part listsone enantiomers (MDW1228 and MDW 1396 are enantiomers and MDW 1248 andMDW 1397 are enantiomers). Both enantiomers of each chiral nonracemiccompound of Scheme 4 are preferred compounds of this invention.

[0217] Table 1 provides exemplary data for a liquid crystal material ofthis invention, specifically for MDW 1248 in combination with a selectedhost mixture MX8058. The exemplified mixture is a combination of 66% byweight MDW1248 and 34% by weight MX8058. Mixture components of MX8058are listed in Scheme 5. Scheme 5 also lists two optional componentsMDW959 and MDW1245 which can be added to produce additional mixtures ofthis invention. MDW 1245 is a chiral nonracemic component that can beadded to enhance the polarization of the mixture. The data in Table 1illustrates V-shaped switching in the exemplary mixture MX9102. Thephase diagram and Ps of the mixture are also given in Table 1.

[0218] Most of the compounds in Scheme 4 show broad antiferroelectricphases above room temperature and a typical tri-state switching wasobserved. V-shaped switching has been found in MDW1228 and 1248 in theirsmectic phases, which have been confirmed to be smectic C phases. Thesetwo compounds can be switched continually in a 2 μm cell using anelectric field below ±1V/μm and the switching angle can reach as largeas 24°. The voltage dependence of switching angle for MDW 1228 is shownin FIG. 1. Although the V-shaped switching phase range is relativelynarrow in these two compounds, their analog electrooptical properties,such as low driving voltage, large switching angle and fast switchingtime, are much better than deformable helix FLCs, electroclinic andnematic materials.

[0219] The smectic A phases in both MDW1228 and 1248 have been verifiedby X-ray diffraction to be de Vries smectic A phases. As shown in FIG.2, molecules in the smectic A phase (of MDW1228) have a more than 30degree tilt and the phase transition from smectic A to C shows only alittle layer spacing shrinkage.

[0220] Both MDW 1228 and MDW 1248 (in appropriate LC mixtures) exhibitV-shaped switching in analog device configurations. Both MDW 1228 andMDW1248 (alone or in appropriate mixtures) form bookshelf geometry in abistable SSFLC device configuration. Both of these compounds possess adeVries smectic A phase which is believed to be characteristic of LCmaterials that exhibit the dual behaviors discussed herein.

[0221] Each of the compounds in Scheme 4 and enantiomers thereof (inappropriate LC mixtures) exhibit V-shaped switching in analog deviceconfigurations. Each of the compounds in Scheme 4 and enantiomersthereof (alone or in appropriate mixtures) form bookshelf geometry in abistable SSFLC device configuration. These compounds possess a deVriessmectic A phase which is believed to be characteristic of LC materialsthat exhibit the dual behaviors discussed herein.

[0222] Table 2A provides data for additional exemplary LC compositionsof this invention containing two or more chiral nonracemic compounds ofFormula 1. The composition of each mixture is provided in Table 2B andthe structures of each component is supplied in Scheme 6. Each of themixtures of Table 2B exhibits bistable behavior as illustrated by theresults (residual tilt angle) of application of a pulsed wave to switchthe state of the LC. The magnitude of the residual or memory tilt angleafter application of the pulsed voltage is an indication of bistablebehavior. A mixture that exhibits a residual tilt angle of 10° is usefulas an LC composition for bistable device applications. Those mixturesexhibiting a residual tilt angle of 15° or more are preferred forbistable device applications and those exhibiting a residual tilt angleof 18°. It will be appreciated by those in the art that more preferredLC materials for bistable devices are those exhibiting a residual tiltangle that is or approaches 22.5° which provides for improved contrastin those devices. LC materials that exhibit lower viscosity and higherpolarization (Ps) are generally preferred. It is generally the case thataddition of chiral nonracemic components that are not compounds ofFormula 1, but are compatible with the compounds of Formula 1 and do notadversely affect the bistable properties of the mixture can be added tomixtures of this invention to increase Ps.

[0223] Components that are compatible in LC mixtures of this inventionin combination with one or more compounds of Formula 1 include LCmolecules with partially or fully fluorinated tail groups and thosehaving tail groups that contain silane groups (e.g., achiral or racemichost mixtures containing compounds with such tails). More specificallythe components of the mixtures of Table 2A are suitable for andcompatible in LC mixtures of this invention containing one or morecompounds of Formula 1. For example, LC mixtures of this inventioninclude those that comprise one or more chiral nonracemic compounds ofFormula 1 (as well as those of Formulas 2A-B and 3A-D) in combinationwith one or more racemic compounds of Formula 1. In a further example,LC mixtures of this invention include those that comprise one or morechiral nonracemic compounds of Formula 1 (as well as those of Formulas2A-B and 3A-D) in combination with one or more of the specificcomponents listed in Scheme 6 or in combination with one or more generalcomponents listed in Scheme 7 (Compounds of formula 7A-G).

[0224] In particular embodiments, mixtures of this invention includethose in which one or more chiral nonracemic compounds of Formula 1 arecombined with one or more chiral nonracemic compounds of Scheme 6 or 7(e.g.,one or more compounds of formulas 7A, 7B, 7C, 7D, enantiomersthereof and mixtures of compounds of formulas 7A-D and any of theirenantiomers) and in further combination with one or more achiral orracemic compounds of Formula 1 or of those compounds listed in Schemes 6and 7 (e.g., one or more compounds of formulas 7E, 7F, 7G, 7H, 7I, 7Jand mixtures thereof). LC mixtures of this invention include thosecontaining one or more components of Formula 1 and one or morecomponents of the formulas listed in Schemes 6 or 7 and which exhibitV-shaped switching in analog device configurations and bistable behaviorin SSFLC devices.

[0225] In more specific embodiments, mixture of this invention includethose which comprise:

[0226] about 5% to about 65% by weight of chiral nonracemic componentsselected from chiral nonracemic compounds of Formula 1 and the chiralnonracemic compounds of Schemes 6 and 7, particularly compounds ofFormula 7A-D, enantiomers thereof, and mixtures of these compounds,where at least 5% by weight of the chiral nonracemic component of themixture is one or more chiral nonracemic compounds of Formula 1;

[0227] about 35% to about 95% by weight of achiral or racemic compoundsof Formula 1, achiral or racemic compounds of Scheme 6 and 7,particularly compounds of Formulas 7E-J and mixtures of these compounds.

[0228] Mixtures of this invention also include those which comprise:

[0229] (1) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0230]  0% to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0231]  a total of about 35% to about 95% of achiral or racemiccompounds comprising:

[0232] 0 to about 15% by weight of one or more compounds of Formula 7F;

[0233] 0 to about 35% by weight of one or more compounds of Formula 7G;and

[0234] about 50% to about 100% by weight of one or more compounds ofFormulas 7E, one or more achiral or racemic compounds of Formula 1 ormixtures thereof;

[0235] (2) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0236]  0% to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0237]  a total of about 35% to about 95% of one or more achiral orracemic compounds of Formula 1;

[0238] (3) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0239]  0% to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0240]  a total of about 35% to about 95% of one or more compounds ofFormulas 7E-7J;

[0241]  (4) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0242]  about 5% to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D;

[0243]  about 5% to about 15% by weight of one or more compounds ofFormula 7F; about 5% to about 35% by weight of one or more compounds ofFormula 7G; and

[0244]  0% to about 80% by weight of one or more compounds of Formulas7E;

[0245] (5) about 5% to about 30% by weight of one or more chiralnonracemic compounds of Formula 1;

[0246]  about 5% to about 20% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0247]  a total of about 50% to about 90% of achiral or racemiccompounds comprising:

[0248] 0 to about 15% by weight of one or more compounds of Formula 7F;

[0249] 0 to about 35% by weight of one or more compounds of Formula 7G;

[0250] 0 to about 25% by weight of one or more compounds of Formula 7H;0 to about 25% by weight of one or more compounds of Formulas 7T or 7Jand

[0251] about 0 to about 100% by weight of one or more compounds ofFormulas 7E, one or more achiral or racemic compounds of Formula 1 ormixtures thereof,

[0252] (6) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0253]  about 5% to about 15% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0254]  a total of about 45% to about 90% of achiral or racemiccompounds comprising:

[0255] 0 to about 15% by weight of one or more compounds of Formula 7E;

[0256] 0 to about 35% by weight of one or more compounds of Formula 7F;and

[0257] about 50% to about 100% by weight of one or more compounds ofFormulas 7D, one or more achiral or racemic compounds of Formula 1 ormixtures thereof,

[0258] (7) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0259]  about 5% to about 15% by weight of one or more chiral nonracemiccompounds of Formulas 7A-C; and

[0260]  a total of about 45% to about 90% of achiral or racemiccompounds of Formulas 7D-7F;

[0261] (8) about 15% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0262]  about 10% to about 25% by weight of one or more chiralnonracemic compounds of Formulas 7A-C; and

[0263]  a total of about 45% to about 75% by weight of one or moreachiral or racemic compounds of Formulas 7D-7F;

[0264] (9) about 40% to about 50% by weight of one or more chiralnonracemic compounds of Formula 1;

[0265]  about 15% to about 25% by weight of one or more achiral orracemic compounds of Formula 7D; and

[0266]  about 25% to about 45% by weight of one or more achiral orracemic compounds of Formula 7F;

[0267] (10) about 30% to about 45% by weight of one or more chiralnonracemic compounds of Formula 1;

[0268]  about 5% to about 15% by weight of one or more chiral nonracemiccompound of Formulas 7A and/or 7B;

[0269]  about 25% to about 45% by weight of one or more achiral orracemic compounds of Formula 7F; and

[0270]  about 10% to about 40% by weight of one or more achiral orracemic compounds of Formula 7D;

[0271] (11) about 20% to about 30% by weight of one or more chiralnonracemic compounds of Formula 1;

[0272]  about 5% to about 15% by weight of one or more chiral nonracemiccompounds of Formulas 7a and/or 7B;

[0273]  about 25% to about 45% by weight of one or more achiral orracemic compounds of Formula 7E; and

[0274]  about 10% to about 50% by weight of one or more achiral orracemic compounds of Formula 7D;

[0275] (12) any of mixtures 1-11 above which also contain 0 to about 25%by weight of a compound of Formula 7G;

[0276] (13) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0277]  0% to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-C; and

[0278]  a total of about 35% to about 95% of achiral or racemiccompounds comprising:

[0279] 0 to about 15% by weight of one or more compounds of Formula 7E;

[0280] 0 to about 35% by weight of one or more compounds of Formula 7F;

[0281] 0 to about 25% by weight of one or more compounds of Formula 7Gand

[0282] about 25% to about 100% by weight of one or more compounds ofFormulas 7D, one or more achiral or racemic compounds of Formula 1 ormixtures thereof;

[0283] (14) about 5% to about 40% by weight of one or more chiralnonracemic compounds of Formula 1;

[0284]  0 to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D; and

[0285]  a total of about 35% to about 95% of one or more compounds ofFormulas 7E-J; and

[0286] (15) about 5% to about 65% by weight of one or more chiralnonracemic compounds of Formula 1;

[0287]  0 to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D;

[0288]  0 to about 25% by weight of one or more chiral nonracemiccompounds of Formulas 7A-D;

[0289]  0 to 25% by weight of one or more compounds of Formulas 7I or7J; and

[0290]  about 35% to about 95% by weight of one or more compounds ofFormula 7E.

[0291] Mixtures of this invention also include those comprising at leastone compound of Formula 1 present in the mixture in an amount of atleast 10% by weight in combination with 5% by weight or more of at leastone compound of Formula 7A-7C and with 5% by weight or more of at leastone compound of Formulas 7D-7G. Mixtures of this invention also includethose comprising at least one compound of Formula 1 present in themixture in an amount of at least 25% by weight in combination with 5% byweight or more of at least one compound of Formula 7A-7C and with 5% byweight or more of at least one compound of Formulas 7D-7G. Mixtures ofthis invention also include those comprising at least two compounds ofFormula 1 present in the mixture in an amount of at least 25% by weightin combination with 5% by weight or more of at least one compound ofFormula 7A-7D and with 5% by weight or more of at least one compound ofFormulas 7E-7J.

[0292] Mixtures of this invention include those that comprise two ormore or three or more chiral nonracemic compounds of Formula 1. Mixturesof this invention further include those that comprises two or more orthree or more compounds of Formula 1 in combination with one or morechiral nonracemic compounds of Formulas 7A, 7B or 7C. it will beappreciated by those of ordinary skill in the art that each of thecompounds of Formulas 1, and 7A-C has two enantiomers. It will also beappreciated that the enantiomer of a pair of enantiomers of a givencomponents selected for combination with other enantiomers in a mixtureshould preferably be selected to achieve the highest polarization (Ps)to provide the fastest switching speed. In the mixtures exemplified inTable 2B, the enantiomers MDW1396 and MDW1397 are combined with eachother or with MDW 1498 (all compounds of Formula 1). Mixture withsimilar properties are obtained by mixing the enantiomers of thesecompounds, i.e., by mixing MDW 1228, MDW 1248 and the enantiomer of MDW1498 (MDW 1498E, see Scheme 4). In other mixtures exemplified in Table2B, the enantiomers MDW1396 and MDW1397 are optionally combined with theenantiomers MDW 1290 and/or MDW 987 and/or MTLC0312. Mixtures withsimilar properties are obtained by mixing the MDW 1228 and/or MDW 1248and/or MDW1498E with the enantiomers of MDW 1290 (MDW1290E) and/or theenantiomer of MDW 987 (MDW987E) and/or the enantiomer of MTLC0312(0312E), see Scheme 6.

[0293] Synthesis of the compounds of this invention is illustrated inthe following examples and in Schemes 8-10. One of ordinary skill in theart can, in view of the disclosures herein and what is well known in theart, readily synthesize the compounds of this invention fromcommercially available starting materials or from materials that areotherwise readily available in the art. Optically active1,1,1-trifluoro-2-alkanols, for example, are described in Jpn. KokaiTokkyo Roho JP 2000 189,197 Chem Abstracts 133:72991m.

[0294] All references cited herein are incorporated by reference hereinto the extent that they are not inconsistent with the descriptionherein.

THE EXAMPLES Example 1 Synthesis of MDW1228 and 1248

[0295] The following descriptions refer to compounds illustrated inSchemes 8 and 9.

7,7,8,8,9,9,10,10,10-Nonafluoro-5-iodo-decanol (2, n is 3)

[0296] To the mixture of 5 g of 5-hexenol and 17.4 g of perfluoroiodobutane, was added 110 mg of AIBN (azobis(isobutyronitrile) at RTunder N₂ atmosphere. After 15 min another 110 mg of AIBN was added. Theresulting solution was then refluxed at 70° C. for 4 hrs. The reactionmixture was cooled down and used for the next reaction without furtherpurification.

7,7,8,8,9,9,10,10-Nonafluoro-decanol(3, n is 3)

[0297] To a solution of 2 g of LAH (lithium aluminum hydride) in 120 mlof ether (abs.), was added slowly ca. 22 g of iodo derivative (2) in 30ml ether (abs.). After addition, the reaction mixture was stirred at RTfor two days and then cooled down to 5° C. in ice water. Water was addedslowly to the reaction mixture until no gas evolved. Solid was filteredthrough a short column of silica gel, washed with ether, ethyl acetate.The filtrates were combined and the solvent was evaporated. The residuewas distilled under vacuum to give 13 g (81% yield) of thepartial-fluoro alcohol (3, n is 3).

7,7,8,8,9,9,10,10,10-Nonafluoro-decyl tosylate(4, l is 3)

[0298] The solution of 9.8 g of partial- fluoro alcohol (3) in 40 ml ofpyridine was cooled down to 0° C. in ice-salt water and 6 g of TsCl(tosyl chloride) was added in small portion. After addition theresulting mixture was stirred at 0C for two hours and then placed infreezer (−20° C.) for two days. The reaction mixture was poured into icewater and the product was extracted with ethyl acetate twice, brine, 10%HCl and again brine three times. The organic solution was dried overMgSO₄ and evaporated to give pure partial-fluoro tosylate (4, n is 3,yield 98%).

[0299] This same procedure is used to synthesize 5, 5, 6, 6, 7, 7, 8,8,-Nonafluoro-octyl tosylate (4, n is 1).

[0300] The following synthesis is general for synthesis of both MDW1228and 1248. The synthesis of MDW1228 employs tosylate 4, where n is 1. Thesynthesis of MDW1248 employs tosylate 4 where n is 3.

1,2-difluoro-3-partialfluoroalkoxybenzene (5)

[0301] 2 mmol of partialfluoroalkyl tosylate (4), 2 mmol of2,3-difluorophenol (19), 2 mmol of Cs₂CO₃ and 20 ml of DMF(N,N-dimethylformamide) were combined and stirred at RT overnight. Thenthe reaction mixture was poured into water and the product was collectedby extraction. The organic solution was washed with brine and dried overMgSO₄. After evaporation of solvent, pure product was obtained in yieldof 100%.

2,3-difluoro-4-partialfluoroalkoxyphenyl boronic acid (6)

[0302] To a dry flask containing 37 mmol of 1,2-difluoro-4-alkoxybenzene (5) and 80 ml of THF (tetrahydrofuran), cooled to −78°C., 21 ml of ButylLi (2.2M in Hexane) was added slowly. After additionthe reaction mixture was stirred at −70° C. for 1 h and then 17.6 ml oftriisopropylborate was added slowly. The reaction solution was allowedto warm up to RT and stirred at RT overnight. Then 70 ml of water wasadded slowly and stirred at RT for two hours. The product was collectedby extraction with hexane. The extract was washed with brine and driedover MgSO₄. After evaporation of solvent, the residue was purified byshort column chromatography to give pure product in yield of 92%.

Ethyl 4-(2,3-difluoro-4-partialfluoroalkoxyphenyl) benzoate (8)

[0303] To the solution of 0.6 g of ethyl 4-bromobenzoate (7) in 7.5 mlof toluene, was added 4 ml of Na₂CO₃ (2M aqueous solution), followed by2.6 mmol 2,3-difluoro-4-partialfluoroalkoxyphenyl boronic acid (7) in 2ml of methanol and 50 mg of Pd(PPh₃)₄(tetrakis(triphenylphoshine)palladium). The resulting mixture was heatedup to 80° C. and stirred at this temperature vigorously for 48 hrs. Itwas then cooled down and partitioned between 15 ml methylene chlorideand 12 ml of 2M aqueous Na₂CO₃. The organic phase was separated, washedwith brine and dried over MgSO₄. After evaporation of solvent, theresidue was purified by flash chromatography. The yield is 86%.

4-(2,3-difluoro4-partialfluoroalkoxyphenyl) benzoic acid (9)

[0304] To a solution of 0.4 g KOH in 20 ml MeOH, was added 1 mmol ofethyl 4-(2,3-difluoro-4-partialfluoroalkoxyphenyl) benzoate(8). Afterthe resulting mixture was refluxed for 4 hrs, the excess methanol wasremoved. The residue was mixed with 30 ml water and extracted with ethertwice. The water solution was acidified with conc. HCl and extractedwith ethyl acetate. The ethyl acetate solution was washed with brine anddried. After evaporation of solvent, pure product was obtained in yieldof 100%.

Ethyl 4-benzyloxybenzoate (11)

[0305] 35 mmol of benzyl bromide (BzBn, 35 mmol of ethyl4-hydroxybenzoate (10), 14 g of Cs₂CO₃ and 40 ml of DMF were combinedand stirred at RT ove night. Then the reaction mixture was poured intowater and the product was collected by extraction. The organic solutionwas washed with brine and dried over MgSO₄. After evaporation ofsolvent, pure product was obtained in yield of 100%.

4-Benzyloxybenzoic acid (12)

[0306] To the solution of 0.5 g KOH in 40 ml MeOH, was added 6.5 mmol ofethyl 4-benzyloxybenzoate. After the resulting mixture was refluxed for4 hrs, the excess methanol was removed. The residue was mixed with 30 mlwater and extracted with ether twice. The water solution was acidifiedwith conc. HCl and extracted with ethyl acetate. The ethyl acetatesolution was washed with brine and dried. After evaporation of solvent,pure product was obtained in quantitative yield.

[R]-1-Trifluoromethylheptyl 4-Benzyloxybenzoate (13)

[0307] To the solution of 7 mmol of 4-benzloxybenzoic acid 12 in 5 ml ofSOCl₂, one drop of DMF was added. The resulting mixture was stirred atrefluxing for two hour. The excess of SOCl₂ was removed and 20 ml ofpyridine was added, followed by 1.2 g of [R]-1-trifluoromethyl heptanol.The resulting mixture was stirred at RT over night and then poured intoice-cold diluted HCl solution. The product was collected by extractionhexane. The organic phase was washed with diluted HCl, water, NaHCO₃solution and brine. After dried over MgSO₄ the solvent was removed andthe residue was purified by flash chromatography to give pure product inyield of 80%.

[R]-1-Trifluoromethylheptyl 4-hydroxybenzoate (14)

[0308] 2.2 g of [R]-1-trifluoromethylheptyl 4-benzyloxybenzoate, (13)100 mg of PdOH/C in 50 ml of ethyl acetate was stirred at RT over nightunder H₂ atmosphere. Then the catalyst was filtered out and filtrate wasevaporated to dryness to give the pure compound in yield of 99%.

[R]-1-Trifluoromethylheptyl4-(4-(2,3-difluoro-4-partialfluoroalkoxyphenyl)phenyl carbonyloxy)) benzoate (15)

[0309] 0.4 mmol of 4-(2,3-difluoro-4-partialfluoroalkoxyphenyl) benzoicacid (14), 0.4 mmol of [R]-1-trifluoromethylheptyl 4-hydroxybenzoate,200 mg of DCC, (1,3-dicyclohexylcarbodiimide) 15 mg of DMAP(4-dimethylaminopyridine) and 20ml of methylene chloride were combinedand stirred at RT over night. The solid was filtered out and thefiltrate was concentrated. The residue was purified by flashchromatography to give pure product with yield over 80%. Compound 15where n is 1 is MDW 1228 and compound 15 where n is 3 is MDW 1248.

Example 2 Synthesis of MDW-1250 and 1449

[0310] In the following description of the preparation of MDW1250compound numbers refer to Scheme10:

2′,3′-Difluoro -4′-(4-pentyloxybutoxy)-biphenyl4 -carboxylic acid 4-[(R)1-trifluoromethylheptyloxycarbonyl]-phenyl ester (28)2-(4-Bromobutoxy)tetrahydropyran (18)

[0311] To a solution of commercially available 4-bromobutan-1-ol (16) (1equi.) and 3,4-dihydropyran (17) (1.5 equi.) in dichloromethane (3mL/mmole), phosphorus oxychloride (0.01 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h. Then potassium carbonate (1 equi.) was added to the reaction mixtureand the reaction mixture was stirred at room temperature for 1 h,quenched with water, extracted with dichloromethane, washed with brine,dried over MgSO₄, and concentrated in vacuo. Purification bychromatography on silica gel (5% EtOAc (ethylacetate)/hexanes) afforded2-(4-bromobutoxy) -tetrahydropyran (18), as a colorless oil (88%).

2-[4-(2,3-Difluorophenoxy)butoxy]-tetrahydropyran (20)

[0312] To a solution of 2-(4-bromobutoxy)-tetrahydropyran (18) (1 equi.)and commercially available 2,3-difluorophenol (19) (1 equi.) in DMF (3mL/mmole), cesium carbonate (1.25 equi.) was added at room temperature.The reaction mixture was stirred at that temperature for 24 h, quenchedwith water, extracted with ethyl acetate:hexane (1:1), washed withbrine, dried over MgSO₄, and concentrated in vacuo. Purification bychromatography on silica gel (5% EtOAc/hexanes) and recrystallizationfrom acetonitrile gave2-[4-(2,3-difluorophenoxy)-butoxy]-tetrahydropyran(20), as a white solid(84%).

4-(2,3-Difluorophenoxy)-butan-1-ol (22)

[0313] To a solution of2-[4-(2,3-difluorophenoxy)-butoxy]-tetrahydropyran (20) (1 equi.) andcommercially available para-toluenesulfonic acid (21) (0.1 equi.) inmethanol:THF (1:1) (3 mL/mmole), water (0.005 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h, quenched with water, extracted with ethyl acetate:hexane (1:1),washed with brine, dried over MgSO₄, and concentrated in vacuo.Purification by chromatography on silica gel (10% EtOAc/hexanes) gave4-(2,3-difluorophenoxy)-butan 1-ol (22), as a white solid (84%)

1,2-Difluoro-3-(4-pentyloxybutoxy)benzene (24)

[0314] Sodium hydride (1 equi.) was added to the solution of4-(2,3-difluorophenoxy)-butan-1-ol (22), (1 equi.) and 1-bromopentane (1equi.) in DMF (1 mL/mmole) and the reaction mixture was stirred at roomtemperature for 12 h,. quenched with water, extracted with ethylacetate:hexane (1:1), washed with brine, dried over MgSO₄, andconcentrated in vacuo. Purification by chromatography on silica gel (5%EtOAc/hexanes) and recrystallization from acetonitrile gave1,2-difluoro-3-(4-pentyloxybutoxy)-benzene (24), as a white solid (84%).

2,3-Difluoro-4-(4-pentyloxybutoxy)phenylboronic acid (25)

[0315] To a solution of 1,2-difluoro-3-(4-pentyloxybutoxy)-benzene (24),(1 equi.) in THF (5 mL/mmole), butyllithium (1.3 equi.) was added at−78° C. The reaction mixture was stirred at that temperature for 2 h,.Then triisopropylborate (1 equi.) was added at that temperature. Thereaction mixture was stirred at that temperature for 1 h and at roomtemperature for 10 h, quenched with water, extracted with ethyl acetate,washed with brine, dried over MgSO₄, and concentrated in vacuo.Purification by recrystallization from hexane gave2,3-difluoro-4-(4-pentyloxybutoxy)phenylboronic acid (25), as a whitesolid (75%).

2′,3′-Difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester 26)

[0316] A biphasic solution of2,3-difluoro-4-(4-pentyloxybutoxy)phenylboronic acid (25) (1 equi.),4-bromo-benzoic acid ethyl ester (12), (1 equi.), sodium carbonate (2.7equi.), and Pd(PPh₃)₄ catalyst (0.01 equi.) in water-toluene (1:1) (2mL/mmole) was stirred at 100 C. temperature for 12 h., cooled to roomtemperature, extracted with ethyl acetate:hexane(1:1), washed withbrine, dried over MgSO4, and concentrated in vacuo. The purification bychromatography on silica gel (5% EtOAc/hexanes) and recrystallizationfrom acetonitrile afforded2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester (26) as a white solid (88%).

4′-(4-Butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27)

[0317] A solution of2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester(26) (1 equi.) and potassium hydroxide (3.5 equi.) in water-ethanol(1:1) (25 mL/mmole) was stirred at 80° C. for 2 h., cooled to roomtemperature, quenched with hydrochloric acid (5%). The resulting whitesolid was filtered, washed with water, and dried under vacuum to give4′-(4-butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27) as awhite solid (80%).

2′,3′-Difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid4-[(R)-1-trifluoromethylheptyloxycarbonyl]-phenyl ester (28)

[0318] To a solution of4′-(4-butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27) (1equi.), (4-hydroxybenzoic acid (R)-1-trifluoromethyl-heptyl ester (7) (1equi.), and DMAP (dimethylaminopyridine) (0.1 equi.) in THF (25mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h, quenched with water, extracted with ethyl acetate:hexane(1:1), washedwith brine, dried over MgSO4, and concentrated in vacuo. Purification bychromatography on silica gel (5% EtOAc/hexanes) gave2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid4-[(R)-1-trifluoromethylheptyl oxycarbonyl]-phenyl ester (28) as a whitesolid (65%).

Preparation of MDW-1497

[0319] Synthesis of2′,3′-difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyloxycarbonyl]-phenylester (36) where all numbers refer to Scheme 9.

(R)-Hept-6-en-2-ol (31)

[0320] To a solution of (R)-2-methyloxirane (29) (1 equi), and copper(I) bromide (0.05 equi.) in THF (2 mL/mmole), a solution ofbut-4-enylmagnesium bromide (30), (0.5M in THF) (1.1 equi.) was added atice temperature over a period of 20 min. The reaction mixture wasstirred at room temperature for 24 h, quenched with 5% aqueous ammoniumchloride (1 mL/mmole), extracted with hexane, washed with brine, driedover MgSO4, and concentrated in vacuo. Purification by chromatography onsilica gel (hexane) gave (R)-hept-6-en-2-ol (31) a colorless oil (96%).

4-Benzyloxybenzoic acid (R)-1-methyl-hex-5-enyl ester (32)

[0321] To a solution of 4-benzyloxy-benzoic acid (4) (1 equi.), (R)-hept-6-en-2-ol (31) (1 equi.), and DMAP (dimethylaminopyridine) (0.1equi.) in THF (25 mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.)was added at room temperature. The reaction mixture was stirred at thattemperature for 24 h, quenched with water, extracted with ethylacetate:hexane(1:1), washed with brine, dried over MgSO4, andconcentrated in vacuo. Purification by chromatography on silica gel (5%EtOAc/hexanes) gave 4-benzyloxybenzoic acid (R)-1-methyl-hex-5-enylester (32) as a colorless oil (65%).

4-Benzyloxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)hexyl ester (34)

[0322] Nitrogen gas was bubbled through the solution of4-benzyloxybenzoic acid (r)-1-methyl-hex-5-enyl ester (32) (1 equi.) And1,1,1,3,3-pentamethyldisiloxane (33) (1.2 equi.) In toluene (10ml/mmole) for 15 min. Pt catalyst (0.001 equi.) Was added to thereaction mixture and nitrogen bubbling was continued for another 15 min.The reaction mixture was stirred at 55 c for 24 h, cooled to roomtemperature, quenched with water, extracted with ethyl acetate:hexane(1:1), washed with brine, dried over MgSO₄, and concentrated in vacuo.Purification by chromatography on silica gel (5% EtOAc/hexanes) afforded4-benzyloxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) hexyl ester (34) awhite solid (96%).

4-Hydroxy-benzoic acid(R)1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)hexyl ester (35)

[0323] A solution of 4-benzyloxy-benzoic acid (Rs1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyl ester (34) (1equi.) and palladium-carbon (10%) (0.01 equi.) in ethyl acetate-ethanol(4:1) (25 mL/mmole) was degassed under vacuum and the reaction mixturewas stirred at room temperature under constant flow of hydrogen gas for14 h. The reaction mixture passed through 2″ celite-silica gel plug toremove Pd-C catalyst, concentrated in vacuo and recrystallized fromacetonitrile-ethanol (3:1) to give 4-hydroxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) hexyl ester (35) as acolorless oil (84%).

2′,3′-Difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)hexyloxycarbonyl]-phenylester (36)

[0324] To a solution of2′,3′-difluoro-4′-(5,5,6,6,7,7,8,8,8-nonafluorooctyloxy)-biphenyl-4-carboxylicacid (9, n is 1) (1 equi.), 4-hydroxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyl ester (35) (1equi.), and DMAP (dimethylaminopyridine) (0.1 equi.) in THF (25mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h, quenched with water, extracted with ethyl acetate:hexane (1:1),washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by chromatography on silica gel (5% EtOAc/hexanes) gave2′,3′-difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid 4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyldisiloxanyl)-hexyloxycarbonyl]-phenylester (36) as a white solid (65%).

Example 2 Synthesis of MDW-1250 and 1449 Preparation of MDW-1250:

[0325] Synthesis of2′,3′-Difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid4-[(R)-1-trifluoromethylheptyloxycarbonyl]-phenyl ester (28), wherecompound numbers refer to Scheme 10:

2-(4-Bromobutoxy)-tetrahydropyran (18)

[0326] To a solution of commercially available 4-bromobutan-1-ol (16) (1equi.) and 3,4-dihydropyran (17) (1.5 equi.) in dichloromethane (3mL/mmole), phosphorus oxychloride (0.01 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h. Then potassium carbonate (1 equi.) was added to the reaction mixtureand the reaction mixture was stirred at room temperature for 1 h,quenched with water, extracted with dichloromethane, washed with brine,dried over MgSO4, and concentrated in vacuo. Purification bychromatography on silica gel (5% EtOAc/hexanes) afforded2-(4-bromobutoxy)-tetrahydropyran (18), as a colorless oil (88%).

2-[4-(2,3-Difluorophenoxy)-butoxy]-tetrahydropyran (20)

[0327] To a solution of 2-(4-bromobutoxy)-tetrahydropyran (18) (1 equi.)and commercially available 2,3-difluorophenol (19) (1 equi.) in DMF (3mL/mmole), cesium carbonate (1.25 equi.) was added at room temperature.The reaction mixture was stirred at that temperature for 24 h, quenchedwith water, extracted with ethyl acetate:hexane (1:1), washed withbrine, dried over MgSO4, and concentrated in vacuo. Purification bychromatography on silica gel (5% EtOAc/hexanes) and recrystallizationfrom acetonitrile gave2-[4-(2,3-difluorophenoxy)-butoxy]-tetrahydropyran(20), as a white solid(84%).

4-(2,3-Difluorophenoxy)-butan-1-ol (22)

[0328] To a solution of2-[4-(2,3-difluorophenoxy)-butoxy]-tetrahydropyran (20) (1 equi.) andcommercially available para-toluenesulfonic acid (21) (0.1 equi.) inmethanol:THF (1:1) (3 mL/mmole), water (0.005 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h, quenched with water, extracted with ethyl acetate:hexane (1:1),washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by chromatography on silica gel (10% EtOAc/hexanes) gave4-(2,3-difluorophenoxy)-butan-1-ol (22), as a white solid (84%).

1,2-Difluoro-3-(4-pentyloxybutoxy)benzene (24)

[0329] Sodium hydride (1 equi.) was added to the solution of4-(2,3-difluorophenoxy)-butan-1-ol (22), (1 equi.) and 1-bromopentane (1equi.) in DMF (1 mL/mmole) and the reaction mixture was stirred at roomtemperature for 12 h,. quenched with water, extracted with ethylacetate:hexane (1: 1), washed with brine, dried over MgSO4, andconcentrated in vacuo. Purification by chromatography on silica gel (5%EtOAc/hexanes) and recrystallization from acetonitrile gave1,2-difluoro-3-(4-pentyloxybutoxy)-benzene (24), as a white solid (84%).

2,3-Difluoro4-(4-pentyloxybutoxy)phenylboronic acid (25)

[0330] To a solution of 1,2-difluoro-3-(4-pentyloxybutoxy)-benzene (24),(1 equi.) in THF (5 mL/mmole), butyllithium (1.3 equi.) was added at−78° C. The reaction mixture was stirred at that temperature for 2 hr,.Then triisopropylborate (1 equi.) was added at that temperature. Thereaction mixture was stirred at that temperature for 1 h and at roomtemperature for 10 h, quenched with water, extracted with ethyl acetate,washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by recrystallization from hexane gave2,3-difluoro-4-(4-pentyloxybutoxy)phenylboronic acid (25), as a whitesolid (75%).

2′,3′-Difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester (26)

[0331] A biphasic solution of2,3-difluoro-4-(4-pentyloxybutoxy)phenylboronic acid (25) (1 equi.),4-bromo-benzoic acid ethyl ester (12), (1 equi.), sodium carbonate (2.7equi.), and tetrakis(triphenylphoshine)palladium catalyst (0.01 equi.)in water-toluene (1:1) (2 mL/mmole) was stirred at 100 C. temperaturefor 12 h., cooled to room temperature, extracted with ethylacetate:hexane(1:1), washed with brine, dried over MgSO4, andconcentrated in vacuo. The purification by chromatography on silica gel(5% EtOAc/hexanes) and recrystallization from acetonitrile afforded2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester (26) as a white solid (88%).

4′-(4-Butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27)

[0332] A solution of2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid ethylester(26) (1 equi.) and potassium hydroxide (3.5 equi.) in water-ethanol(1:1) (25 mL/mmole) was stirred at 80 C. temperature for 2 h., cooled toroom temperature, quenched with hydrochloric acid (5%). The resultingwhite solid was filtered, washed with water, and dried under vacuum togive 4′-(4-butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27)as a white solid (80%).

2′,3′-Difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid4-[(R)-1-trifluoromethylheptyloxycarbonyl]-phenyl ester (28)

[0333] To a solution of4′-(4-butoxybutoxy)-2′,3′-difluorobiphenyl-4-carboxylic acid (27) (1equi.), (4-hydroxybenzoic acid (R)-1-trifluoromethyl-heptyl ester (13,Scheme 7) (1 equi.), and DMAP (dimethylaminopyridine) (0.1 equi.) in THF(25 mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.) was added atroom temperature. The reaction mixture was stirred at that temperaturefor 24 h, quenched with water, extracted with ethyl acetate:hexane(1:1),washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by chromatography on silica gel (5% EtOAc/hexanes) gave2′,3′-difluoro-4′-(4-pentyloxybutoxy)-biphenyl-4-carboxylic acid4-[(R)-1-trifluoromethylheptyloxycarbonyl]-phenyl ester (28) as a whitesolid (65%).

Preparation of MDW-1497:

[0334] Synthesis of2′,3′-Difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid 4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyloxycarbonyl]-phenyl ester (36) where all numbers refer to Scheme11.

(R-Hept-6-en-2-ol (31)

[0335] To a solution of (R)-2-methyloxirane (29) (1 equi), and copper(I) bromide (0.05 equi.) in THF (2 mL/mmole), a solution ofbut-4-enylmagnesium bromide (30), (0.5M in THF) (1.1 equi.) was added atice temperature over a period of 20 min. The reaction mixture wasstirred at room temperature for 24 h, quenched with 5% aqueous ammoniumchloride (1 mL/mmole), extracted with hexane, washed with brine, driedover MgSO4, and concentrated in vacuo. Purification by chromatography onsilica gel (hexane) gave (R)-hept-6-en-2-ol (31) a colorless oil (96%).

4-Benzyloxybenzoic acid (R)-1-methyl-hex-5-enyl ester (32)

[0336] To a solution of 4-benzyloxy-benzoic acid (4) (1 equi.),(R)-hept-6-en-2-ol (31) (1 equi.), and DMAP (dimethylaminopyridine) (0.1equi.) in THF (25 mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.)was added at room temperature. The reaction mixture was stirred at thattemperature for 24 h, quenched with water, extracted with ethylacetate:hexane(l :1), washed with brine, dried over MgSO4, andconcentrated in vacuo. Purification by chromatography on silica gel (5%EtOAc/hexanes) gave 4-benzyloxybenzoic acid (R)-1-methyl-hex-5-enylester (32) as a colorless oil (65%).

4-Benzyloxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) -hexyl ester (34)

[0337] Nitrogen gas was bubbled through the solution of4-benzyloxybenzoic acid (R)-1-methyl-hex-5-enyl ester (32) (1 equi.) and1,1,1,3,3-pentamethyldisiloxane (33) (1.2 equi.) in toluene (10mL/mmole) for 15 min. Pt catalyst (0.001 equi.) was added to thereaction mixture and nitrogen bubbling was continued for another 15 min.The reaction mixture was stirred at 55 C. for 24 h, cooled to roomtemperature, quenched with water, extracted with ethyl acetate:hexane(1:1), washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by chromatography on silica gel (5% EtOAc/hexanes) afforded4-benzyloxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) -hexyl ester (34) awhite solid (96%).

4-Hydroxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) -hexyl ester (35)

[0338] A solution of 4-benzyloxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyl ester (34) (1equi.) and palladium-carbon (10%) (0.01 equi.) in ethyl acetate-ethanol(4:1) (25 mL/mmole) was degassed under vacuum and the reaction mixturewas stirred at room temperature under constant flow of hydrogen gas for14 h. The reaction mixture passed through 2″ celite-silica gel plug toremove Pd-C catalyst, concentrated in vacuo and recrystallized fromacetonitrile-ethanol (3:1) to give 4-hydroxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl) -hexyl ester (35) asa colorless oil (84%).

2′,3′-Difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)hexyloxycarbonyl]-phenylester (36)

[0339] To a solution of2′,3′-difluoro-4′-(5,5,6,6,7,7,8,8,8-nonafluoro-octyloxy)-biphenyl-4-carboxylicacid (9, Scheme 7) (1 equi.), 4-hydroxy-benzoic acid(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyl ester (35) (1equi.), and DMAP (dimethylaminopyridine) (0.1 equi.) in THF (25mL/mmole), DIC (diisopropyl carbodiimide) (1.2 equi.) was added at roomtemperature. The reaction mixture was stirred at that temperature for 24h, quenched with water, extracted with ethyl acetate:hexane (1:1),washed with brine, dried over MgSO4, and concentrated in vacuo.Purification by chromatography on silica gel (5% EtOAc/hexanes) gave2′,3′-difluoro-4′-(6,6,7,7,8,8,9,9,9-nonafluoro-nonyl)-biphenyl-4-carboxylicacid4-[(R)-1-methyl-6-(1,1,3,3,3-pentamethyl-disiloxanyl)-hexyloxycarbonyl]-phenylester (36) as a white solid (65%).

[0340] Those of ordinary skill in the art will appreciate that materialsand methods other than those specifically exemplified herein can beemployed in the practice of this invention without expense of undueexperimentation. All materials and methods known or understood in theart to be functional equivalents of the materials and methodsexemplified herein are intended to be encompassed by this invention.

Scheme 4: EXEMPLARY COMPOUNDS OF THIS INVENTION MDW# STRUCTURE 1228

1229

1236

1237

1248

1252

1253

1254

1497

1498

1249

1250

1251

1396

1397

1498E

[0341] Scheme 5 COMPOSITION OF MX8058¹ MDW# STRUCTURE Weight %  336

12  576

12  577

12   3

12.8   4

12.8   5

12.8   6

12.8  31

12.8  959²

NA³ 1245² 

NA³

[0342] Scheme 6: Components for Mixtures of Tables 2A and 2B MWD No.STRUCTURE 1290

1290E

 987

 987E

MTLC 0312

0312E

 959

1441

1568

 538

1567

1795

1744

1591

1595

1586

1596

1608

1632

[0343]

TABLE 1 Switching Angle MX9102¹ as a Function of Electric Field andTemperature Temperature Electric Field (V/μm) (°C.) 0.5 1 1.5 2.0 2.53.0 3.5 30 5 9.5 14.6 20.3 23.3 24.6 25 40 5 10 15.4 20.2 22.6 24 24.245 5 12.5 18.8 20.5 22.5 23.4 23.5

[0344] TABLE 2A Electro-optical properties of deVries Type BistableCompositions LV-050 at RT Pulse wave Electric Square wave 5 V/μm, Phasediagram rise time Viscosity Ps 2.5 V/μm, 100 Hz 100 Hz, 400 μs MX (°C.)(μs) (mP*S) (nC/cm²) è ô è ô 9136 I 91-87 A 70.5 C. 437 477 32.7 27.8220 18 130 9136y I 94-91 A 68.5 C. 160 290 49.2 22.9 180 15.5 115 9137 I95-92 A 72 C. 230 464 54.6 26.7 131 15.2 80 9149 I 95-93 A 69.5 C. 265435 47 26.5 140 13 70 9157 I 95-93 A 77 C. 335 318 27 26 210 16 90 9159I 96-94.5 A 74 C. 202 282 38.7 9163 I 93.7-89 A 67 C. 125 213 40.3 22.4120 9165 I 94-90 A 70.5 C. 135 214 40.5 23 123 9166 I 92-88 A 71.5 C.135 200 39 23.5 133 14.3 62 9170 I 94.5-92 A 71 C. 150 233 43 23.1 12015.5 56 9171 I 93-90.5 A 73.5 C. 165 282.6 40.9 23.7 123 16.4 60 9172 I93.6-91.5 A 75.5 C. 125 190 33 22.9 127 14.4 65 9173 I 93.5-91 A 74.5 C.127 186 34.5 23.5 126 15.2 58 9195 I 95-93.5 A 77 C. 110 214 45.5 23.885 9196 I 93.7-91.5 A 72 C. 105 159 36.7 22.4 144 17 55 9197 I 93.7-91.5A 66.5 C. 112 134 31.4 19.5 120 9198 I 93.5-91.5 A 72.5 C. 162 206 34.723.7 210

[0345] TABLE 2B De Vries Type Bistable Mixture Compositions CompositionMDW MTAX A-2 A-2 MX 1396 1397 1498 959 1441 1568 538 1567 1290 987 0312028 032 1591 1595 1586 1596 1608 1632 9136 10 20 15 10 10 10 21 4 9136y8.5 17 12.8 8.5 8.5 8.5 17.8 3.4 15 9137 15 25 5 15 10 5 15 5 5 9149 1020 10 10 15 15 10 10 9157 10 15 10 10 15 10 10 10 10 9159 9 13.5 9 913.5 9 9 10 9 9 9163 10 20 5 10 15 15 10 10 5 9165 9.5 19 4.7 9.5 14.314.3 9.5 9.5 4.7 5 9166 9 18 4.5 9 13.5 13.5 9 9 4.5 10 9170 10 20 10 1215 10 7 8 8 9171 9 18 9 10.8 13.5 9 6.3 10 7.2 7.2 9172 7 8 10 10 15 1215 5 10 8 9173 6.7 12.6 9.5 9.5 14.2 11.5 14.2 4.8 9.5 7.6 9195 10 15 1012 13 12 7 15 6 9196 10 15 10 10 15 10 9.1 10.7 5.8 4.4 9197 10 15 10 810 10 7 10 5 5 10 9198 8 16 8 9.6 12 8 5.6 10 6.4 6.4 10

We claim:
 1. A liquid crystal compositions which comprises one or morecompounds of the formula:

wherein: R is a linear or branched perfluorinated or partiallyfluorinated alkyl group (R^(F)), a linear, cyclic or branchedperfluorinated or partially fluorinated ether group or a linear orbranched ether group; Rings A, B and C are 5- or 6-carbon aromatic ringseach optionally substituted with from one to four fluorines and whereinone or two CH groups in the rings can be substituted with a N, an O or aS group; d is 0 or 1; D is a linker group selected from the groupconsisting of —COO—, —OOC—, —CH₂—CH₂—, a cis or trans double bond, or atriple bond, when d is 0 rings B and C are linked through a single bond;Y is an alkyl or fluorinated alkyl group having from one to six carbonatoms; and R¹ is a nonchiral tail group selected from linear or branchedalkyl groups where one or more non-neighboring CH₂ groups can bereplaced with an —O—, —S—, —Si(R′)₂—, —Si(R′)₂—(CH₂)_(p)—Si(R′)₂—, wherep is an integer ranging from 1 to 6, —Si(R′)₂—O—, —Si(R′)₂—O—Si(R′)₂—O—,a cis or trans double bond or a triple bond, wherein each R′,independent of other R′, is an alkyl or fluorinated alkyl group havingfrom one to six carbon atoms and wherein the R¹ tail group is optionallysubstituted with one or more fluorines.
 2. The liquid crystalcomposition of claim 1 which exhibits a de Vries smectic A phase.
 3. Theliquid crystal composition of claim 1 which exhibits V-shaped switchingwhen incorporated as aligned layer in an analog liquid crystal device.4. The liquid crystal composition of claim 1 wherein the core rings A, Band C are selected from the group consisting of phenyls,fluorine-substituted phenyls, pyridines and pyrimidines.
 5. The liquidcrystal composition of claim 4 wherein d is 1 and D is —COO— or —OOC—.6. The liquid crystal composition of claim 5 wherein Y is an alkyl orperfluorinated alkyl group having 1 to 3 carbon atoms.
 7. The liquidcrystal composition of claim 6 wherein R is an ether, a partiallyfluorinated ether or a perfluorinated ether.
 8. The liquid crystalcomposition of claim 6 wherein R is RF.
 9. The liquid crystalcomposition of claim 8 wherein Re has the formula:C_(n)F_(2n+1)C_(m)H_(2m)-wherein n is an integer ranging from 1 to about10 and m is an integer ranging from 1 to about
 10. 10. The liquidcrystal composition of claim 8 wherein R^(F) has the formula:C_(n)F_(2n+1)C_(m)H_(2m) wherein n is an integer ranging from 1 to about20 and m is an integer ranging from 0 to about
 10. 11. The liquidcrystal composition of claim 1 wherein d is 1 and D is —CH₂—CH₂—. 12.The liquid crystal composition of claim 1 further comprising one or morecomponents having any of the formulas:

where x and y, independent of x and y in other components, are integersranging from 1 to 10 inclusive; R′ is a lower alkyl group having from 1to 6 carbon atoms; R is an achiral or racemic alkyl group having from 3to 20 carbon atoms, R^(F) is a perfluorinated alkyl group or partiallyfluorinated group having 1 to 20 carbon atoms.
 13. The mixture of claim12 wherein the one or more components of the listed formulas are presentin a total amount of about 25% by weight or more of the mixture.
 14. Theliquid crystal composition of claim 12 further comprising one or morecomponents having the formulas:

where x is 0 or 1, indepedent of x in other components, h is an integerfrom 1 to 10, R is an alkyl group having from 3 to about 20 carbonaatoms, R^(F) is a perfluorinated alkyl group or partially fluorinatedgroup having 1 to 20 carbon atoms.
 15. The liquid crystal composition ofclaim 12 further comprising one or more components having the formulas:

where j is an integer that ranges from 2 to 10, inclusive, and R is analkyl group having from 3 to 20 carbon atoms.
 16. The liquid crystalcomposition of claim 15 further comprising one or more components havingthe formula:

wherein R′ is a lower alkyl group having from 1 to 6 carbon atoms. 17.The liquid crystal composition of claim 12 which has a total number ofcomponents of 5 or more.
 18. The liquid crystal composition of claim 1which comprises a first chiral nonracemic component which comprises oneor more chiral nonracemic compounds of the formula.
 19. The liquidcrystal composition of claim 16 further comprising a second chiralnonracemic component which comprises one or more chiral nonracemiccompounds selected from the group of compounds having formulas:

or enatiomers thereof where R is an alkyl group having from 2 to about20 carbon atoms, R* is a chiral nonoracemic branched alkyl group havingfrom 3 to about 20 carbon atoms, and R^(F) is a perfluoroalky or apartially fluorinated alkyl groups having from 3 to about 20 carbonatoms.
 20. The liquid crystal composition of claim 19 wherein the secondchiral nonracemic component is present in the mixture at a level of atleast about 10% by weight.
 21. The liquid crystal composition of claim19 further comprising an achiral or racemic component which comprisesone or more compounds having the formulas

z is 1 or 0, x and y, independent of x and y in other components rangefrom 1 to 20, h is an integer ranging from 1-10, j is an integer rangingfrom 2-20, R is an alkyl group (linear or branched) having from 3 to 20carbon atoms; R^(F) is a partially fluorinated or perfluorinated tailgroup and R′ is a lower alkyl group having from 1 to 6 carbon atoms. 22.The liquid crystal composition of claim 21 which contains a total numberof components of 5 or more.
 23. The liquid crystal composition of claim21 which contains at least one component of each formula listed.
 24. Theliquid crystal composition of claim 1 wherein R is R^(F).
 25. The liquidcrystal composition of claim 24 wherein Y is an alkyl or fluorinatedalkyl group having from 1 to 3 carbon atoms.
 26. The liquid crystalcomposition of claim 25 wherein Y is CF₃.
 27. The liquid crystalcomposition of claim 26 wherein R¹ is an alkyl group.
 28. The liquidcrystal composition of claim 27 wherein R¹ is an alkyl group having from4 to 8 carbon atoms.
 29. The liquid crystal composition of claim 26wherein the rings A, B and C are phenyl rings or fluorine-substitutedphenyl rings.
 30. The liquid crystal composition of claim 29 wherein dis 1 and D is —COO— or —OOC—.
 31. The liquid crystal composition ofclaim 26 wherein at least one of rings A, B or C is a pyridine or apyridine ring.
 32. The liquid crystal composition of claim 31 wherein dis 1 and D is —COO— or —OOC—.
 33. The liquid crystal composition ofclaim 26 wherein R¹ contains one or more Si atoms.
 34. The liquidcrystal composition of claim 33 wherein R¹ has the formula:Si(R′)₂—(CH₂)_(p)—Si(R′)₂— where p is 1-6 and R′ is a small alkyl grouphaving from 1 to 3 carbon atoms.
 35. The liquid crystal composition ofclaim 33 wherein: R¹ contains a —Si(R′)₂—CH₂—Si(R′)₂— group where R′ isa small alkyl group having from 1 to 3 carbon atoms.
 36. The liquidcrystal composition of claim 33 wherein: R¹ contains a —Si(R′)₂—O— groupwhere R′ is a small alkyl group having from 1 to 3 carbon atoms.
 37. Theliquid crystal composition of claim 33 wherein: R₁ contains a—Si(R′)₂—O—Si(R′)₂— group where R′ is a small alkyl group having from 1to 3 carbon atoms.
 38. The liquid crystal composition of claim 1 whereinY is CF₃.
 39. The liquid crystal composition of claim 38 wherein R¹ isan alkyl group.
 40. The liquid crystal composition of claim 38 whereinR¹ contains a PDMS group.
 41. The liquid crystal composition of claim 40wherein rings A, B and C are phenyl rings or fluorine-substituted phenylrings.
 42. The liquid crystal composition of claim 40 wherein R isR^(F).
 43. The liquid crystal composition of claim 1 wherein R is anether having the formula C_(q)H_(2q+1)—O—C_(r)H_(2r)—, where q and r areintegers from 1 to
 20. 44. The liquid crystal composition of claim 43wherein Y is CF₃.
 45. The liquid crystal composition of claim 44 whereinR¹ is an alkyl group.
 46. The liquid crystal composition of claim 45wherein rings A, B and C are selected from the group consisting ofphenyls, fluorine-substituted phenyls, pyridines and pyrimidines. 47.The liquid crystal composition of claim 46 wherein rings A, B and C areselected from the group consisting of phenyl rings, orfluorine-substituted phenyl rings.
 48. The liquid crystal composition ofclaim 1 wherein R is an ether having the formula:C_(q)H_(2q+1)—O—C_(r)H_(2r)—O—C_(s)H_(2s)—, where q, r and s areintegers from 1 to
 20. 49. The liquid crystal composition of claim 1which exhibits a Ps of 27 nC/cm² or greater.
 50. The liquid crystalcomposition of claim 1 which exhibits a Ps of 40 nC/cm² or greater. 51.The liquid crystal composition of claim 1 which when introduced as analigned layer in a liquid crystal device exhibits an electric rise timeof 150 μ sec or less.
 52. The liquid crystal composition of claim 1which exhibits viscosity of 200 mP*S or less.
 53. The liquid crystalcomposition of claim 1 which exhibits a smectic A phase which extendsover a range of 20° C. or more.
 54. The liquid crystal composition ofclaim 1 which exhibits both a smectic A and a smectic C phase.
 55. Theliquid crystal composition of claim 54 which exhibits a smectic C phasewith a temperature range encompassing room temperature.
 56. A compoundhaving the formula:

wherein: R is a linear or branched perfluorinated or partiallyfluorinated alkyl group (R^(F)), a linear, cyclic or branchedperfluorinated or partially fluorinated ether group or a linear orbranched ether group; Rings A, B and C are 5- or 6-carbon aromatic ringsrings each optionally substituted with from one to four fluorines andwherein one or two CH groups in the rings can be substituted with a N,an O or a S group; d is 0 or 1; D is a linker group selected from thegroup consisting of —COO—, —OOC—, a cis or trans double bond, or atriple bond, when d is 0 rings B and C are linked through a single bond;Y is an alkyl or fluorinated alkyl group having from one to six carbonatoms; and R¹ is a nonchiral tail group selected from linear or branchedalkyl groups where one or more non-neighboring CH₂ groups can bereplaced with an —O—, —S—, —Si(R′)₂—, —Si(R′)₂—(CH₂)_(p)—Si(R′)₂—, wherep is an integer ranging from 1 to 6, —Si(R′)₂—O—, —Si(R′)₂—O—Si(R′)₂—O—, a cis or trans double bond or a triple bond,wherein each R′, independent of other R′, is an alkyl or fluorinatedalkyl group having from one to six carbon atoms and wherein the R¹ tailgroup is optionally substituted with one or more fluorines.
 57. Thecompound of claim 56 wherein Y is CF₃ and R is R^(F).
 58. The compoundof claim 57 wherein R^(F) is a partially fluorinated tail
 59. Thecompound of claim 58 wherein R^(F) has the formulaC_(n)F_(2n+1)C_(m)H_(2m)— wherein n is an integer ranging from 1 toabout 10 and m is an integer ranging from 1 to about
 10. 60. Thecompound of claim 59 wherein R^(F) is C₄F₉C₄H₈—.
 61. The compound ofclaim 59 wherein R^(F) is C₄F₉C₆H₁₂—.
 62. The compound of claim 59 whererings A, B, and C are selected from the group consisting of phenylgroups and fluorine-substituted phenyl groups.
 63. An electroopticaldevice comprising an aligned liquid crystal layer which comprises theliquid crystal composition of claim
 1. 64. The electrooptical device ofclaim 63 wherein the device exhibits bistable switching.
 65. The deviceof claim 64 which is an analog device exhibiting V-shaped switching. 66.An electrooptical device comprising an aligned layer which comprises theliquid crystal composition of claim 1 and which can be operated at lowdriving voltages at high frequency and using a symmetrical drivingscheme for DC balance.
 67. A method for making a bistable liquid crystalelectrooptical device which comprises the step of aligning a liquidcrystal composition of claim 1 which exhibits a de Vires smectic A phasein a bookshelf alignment in the device.
 68. A method for making anelectrooptical device that exhibits analog switching which comprises thestep of aligning a liquid crystal composition of claim 1 which exhibitsV-shaped switching in the device.
 69. A method for making a liquidcrystal composition which exhibits both bistable switching and V-shapedswitching which comprises the step of combining one or more chiralnonracemic compounds of claim 1 with one or more liquid crystalcompounds which have one or both tail groups that are partiallyfluorinated or that contain one or more Si atoms.
 70. The method ofclaim 69 wherein about 25% to about 65% of a chiral nonracemic compoundof claim 1 is combined to form the liquid crystal composition.